Temperature-controlled cargo containers, such as refrigerated trailers, are commonly used to transport food products and other temperature-sensitive products. A refrigerated trailer generally includes a refrigeration unit mounted to the front wall of the trailer with inlet and outlet portions protruding into the interior of the trailer. The outlet of the refrigeration unit forces cooled air into the trailer near the ceiling of the trailer, thus causing the cooled air to cycle through the trailer. The inlet of the refrigeration unit is positioned below the outlet in order to receive air that has cycled though the trailer. In some circumstances, the cooled air from the outlet may “short cycle” and not flow sufficiently to the rear of the trailer, which can causes a substantial temperature gradient in the trailer. To prevent the cooled air from leaving the outlet of the refrigeration unit and short cycling immediately to the inlet, a duct system may be installed along the ceiling of the trailer and an air return bulkhead may be installed on the front wall. The duct system guides the cooled air from the outlet of the refrigeration unit toward the rear portion of the trailer. The air return bulkhead effectively funnels the air near the floor of the trailer to the inlet of the refrigeration unit, reducing the likelihood that the cooled air forced from the outlet near the ceiling will short cycle to the inlet.
Typically, air return bulkheads are mounted to the front wall of the trailer using rivets or screws. Installation or removal of these bulkheads requires the use of handheld tools such as drills and fastener drivers. Conventional bulkheads rely on this method of installation primarily due to its simplicity and low cost.
However, as the air return bulkhead guides the cycled air from the floor of the trailer to the inlet of the refrigeration unit, debris and other objects may become lodged in a filter disposed in the bulkhead plenum or at the inlet of the refrigeration unit. This debris may restrict the airflow path and thereby reduce the efficiency and effectiveness of the temperature control system. More significantly, however, the presence of debris minimizes the heat transfer in the refrigeration unit and thus places the unit under considerable strain. The refrigeration unit may fail if such a condition persists, which in turn may necessitate costly repairs.
To remove the debris and clean out the air return path in the bulkhead (or to perform maintenance and repair at the inlet of the refrigeration unit), the bulkhead or a substantial portion thereof is removed from front wall of the trailer. The removal or disassembly of the bulkhead is often time-consuming and inconvenient, as it commonly involves the use of handheld tools and the removal of multiple fasteners.